The problem is that I fear that it might be impossible to make JogAmp work with both versions (8 and 11). The least annoying scenario that I see is that your changes to make it work with Java 11 prevents from building it with Java 8 but doesn't prevent from running it with Java 8 except the part of GlueGen that doesn't belong to its runtime (GlueGen RT).

Have you uploaded the fat JAR of your build somewhere? I'd like to give it a try.